For Frege’s general views about truth the standard reference is the first couple of pages of ‘The Thought’. Less attention has been paid to a short passage in ‘On Sense and Reference’ -- in, fact, only one paragraph long -- where Frege argues indirectly for the view that the relation between the thought and the True is an instance of the relation between sense and reference. He argues for this by discrediting the alternative view that it is an instance of (...) the relation between “subject and predicate”. Here is the paragraph: One might be tempted to regard the relation of the thought to the True not as that of sense to reference, but rather as that of subject to predicate. One can, indeed, say: ‘The thought, that 5 is a prime number, is true’. But closer examination shows that nothing more has been said than in the simple sentence ‘5 is a prime number’. The truth claim arises in each case from the form of the declarative sentence, and when the latter lacks its usual force, e.g. in the mouth of an actor upon stage, even the sentence ‘The thought that 5 is a prime number is true’ contains only a thought, and indeed the same thought as the simple ‘5 is a prime number’. It follows that the relation of the thought to the True may not be compared with that of subject and predicate. Subject and predicate (understood in the logical sense) are indeed elements of thoughts; they stand on the same level for knowledge. By combining subject and predicate, one reaches only a thought, never passes from sense to reference, never from thought to its truth value. One moves at the same level but never advances from one level to the next. A truth value cannot be part of a thought, any more than, say, the Sun can, for it is not a sense but an object. (Frege 1892, pp 34-35). Two subordinate, but still major, positive ideas are expressed in this passage. (shrink)